Production diversification is one way to avoid losses due to market variations. Melons are among the species used for this purpose, however, little information is a limiting factor to production stimulation. The objective of this study was to estimate and evaluate the economic indicators of muskmelon (Cucumis melo L.) cultivation, defining the most appropriate plant spacing in the planting line. A randomized complete block design was used, with four replications of five treatments corresponding to planting spacing of 15, 25, 35, 45 and 55 cm. From the production data of each treatment, economic indicators related to costs and returns obtained with the melon crop were estimated. For the production of melons in a protected area of 300 m2, a total operating cost of $ 440.02 per production cycle was obtained. This amount was constituted by investments in manual operations, inputs, other expenses and interest of cost, which had a participation of 60.60%, 31.78%, 4.62% and 3.00%. The highest values of the economic indicators and the lower equilibrium and productivityprices were obtained for melons spaced 55 cm. The cultivation of muskmelons spaced 55 cm in the planting lines provides greater economic gains for this culture. This species can be used by farmers as an alternative to crops commonly grown in systems protected environment, but continuing studies should be performed to allow greater financial performance by optimizing the production system.